Thread-like knife for tissue cutting

ABSTRACT

An end effector assembly for use with an electrosurgical instrument is provided. The end effector assembly includes a pair of opposing jaw members configured to grasp tissue therebetween. The assembly also includes a thread-like member having a first end coupled to at least one jaw member and a drive member coupled to a second end of the thread-like member. The drive member is configured to position the thread-like member between a first position and a second position, wherein the thread-like member cuts tissue when positioned in the second position.

BACKGROUND

1. Technical Field

The present disclosure relates to electrosurgical instruments used for open and endoscopic surgical procedures for sealing or fusing tissue. More particularly, the present disclosure relates to a bipolar forceps used in an energy based sealing instrument and configured to cut tissue, and, in particular, cut tissue using a thread-like knife.

2. Background of the Related Art

Open or endoscopic electrosurgical forceps utilize both mechanical clamping action and electrical energy to effect hemostasis. The electrode of each opposing jaw member is charged to a different electric potential such that when the jaw members grasp tissue, electrical energy can be selectively transferred through the tissue. A surgeon can cauterize, coagulate/desiccate and/or simply reduce or slow bleeding, by controlling the intensity, frequency and duration of the electrosurgical energy applied between the electrodes and through the tissue.

Certain surgical procedures require more than simply cauterizing tissue and rely on the combination of clamping pressure, electrosurgical energy and gap distance to “seal” tissue, vessels and certain vascular bundles. More particularly, vessel sealing or tissue sealing utilizes a unique combination of radiofrequency (RF) energy, clamping pressure and precise control of gap distance (i.e., distance between opposing jaw members when closed about tissue) to effectively seal or fuse tissue between two opposing jaw members or sealing plates. Vessel or tissue sealing is more than “cauterization”, which involves the use of heat to destroy tissue (also called “diathermy” or “electrodiathermy”). Vessel sealing is also more than “coagulation”, which is the process of desiccating tissue wherein the tissue cells are ruptured and dried. “Vessel sealing” is defined as the process of liquefying the collagen, elastin and ground substances in the tissue so that the tissue reforms into a fused mass with significantly-reduced demarcation between the opposing tissue structures.

Many electrosurgical instruments include a cutting member for cutting sealed tissue. Existing methods involve the use mechanical or electrical cutting actions. For example, a knife may be included in an electrosurgical instrument. The knife is designed to cut a thin layer of tissue grasped between jaws. Conventional instruments do not allow use of the knife unless the jaws are closed. However, sometimes there is a need for cutting and sealing thicker tissues where the jaws cannot completely close and the thicker tissue has to be cut without sealing.

SUMMARY

In an embodiment of the present disclosure, an end effector assembly is provided. The end effector assembly includes a pair of opposing jaw members configured to grasp tissue therebetween. The assembly also includes a thread-like member having a first end coupled to at least one jaw member and a drive member coupled to a second end of the thread-like member. The drive member is configured to position the thread-like member between a first position and a second position, wherein the thread-like member cuts tissue when positioned in the second position.

The drive member may include a drive shaft having a spring component and at least one guiding roll configured to hold the second end of the thread like member and guide the thread-like member between the first position and the second position.

The thread-like member may be a bow shaped spring that is coupled to at least one jaw member with a hinge. A cutting portion of the thread-like member may be formed from twisted filaments, include a resistive conductor or include a fiber waveguide such as an optical fiber. The optical fiber may include a side-lit fiber or a long period fiber grating.

In yet another embodiment of the present disclosure another electrosurgical instrument for sealing tissue is provided. The end effector assembly includes a pair of opposing jaw members configured to grasp tissue therebetween. The assembly also includes a thread-like member formed as a continuous loop and a drive member. The drive member is configured to position the thread-like member between a first position and a second position, wherein the thread-like member cuts tissue when positioned in the second position. A drive drum may also be provided that is operatively coupled to the thread-like member and configured to move the thread-like member to cut tissue between the pair of opposing jaw members.

In another embodiment of the present disclosure, a method for cutting tissue using an end effector assembly including a pair of opposing jaw members and a thread-like member is provided. The method includes sealing tissue between the pair of opposing jaw members, and activating a drive member to move the thread-like member distally and cut the sealed tissue.

BRIEF DESCRIPTION OF THE DRAWINGS

Objects and features of the presently disclosed systems and methods will become apparent to those of ordinary skill in the art when descriptions of various embodiments thereof are read with reference to the accompanying drawings, of which:

FIG. 1 is a right, perspective view of an endoscopic bipolar forceps having a housing, a shaft and a pair of jaw members affixed to a distal end thereof, the jaw members including an electrode assembly disposed therebetween;

FIG. 2 is a left, perspective view of an open bipolar forceps showing a pair of first and second shafts each having a jaw member affixed to a distal end thereof with an electrode assembly disposed therebetween;

FIG. 3 is a right perspective view of an end effector assembly according to an embodiment of the present disclosure;

FIGS. 4A and 4B are schematic views of an end effector assembly according to an embodiment of the present disclosure;

FIGS. 5A and 5B are schematic views of an end effector assembly according to another embodiment of the present disclosure;

FIGS. 6A and 6B are schematic views of an end effector assembly according to another embodiment of the present disclosure; and

FIG. 7 is a schematic view of an end effector assembly according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

Particular embodiments of the present disclosure are described hereinbelow with reference to the accompanying drawings; however, the disclosed embodiments are merely examples of the disclosure and may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure. Like reference numerals may refer to similar or identical elements throughout the description of the figures.

Electromagnetic energy is generally classified by increasing frequency or decreasing wavelength into radio waves, microwaves, infrared, visible light, ultraviolet, X-rays and gamma-rays. As used herein, the term “microwave” generally refers to electromagnetic waves in the frequency range of 300 megahertz (MHz) (3×10⁸ cycles/second) to 300 gigahertz (GHz) (3×10¹¹ cycles/second). As used herein, the term “RF” generally refers to electromagnetic waves having a lower frequency than microwaves. As used herein, the term “ultrasound” generally refers to cyclic sound pressure with a frequency greater than the upper limit of human hearing. The terms “tissue” and “vessel” may be used interchangeably since it is believed that the present disclosure may be employed to seal and cut tissue or seal and cut vessels utilizing the same principles described herein.

As will be described in more detail below with reference to the accompanying figures, the present disclosure is directed to the of a thread like knife to cut tissue.

Referring now to FIGS. 1 and 2, FIG. 1 depicts a bipolar forceps 10 for use in connection with endoscopic surgical procedures and FIG. 2 depicts an open forceps 100 contemplated for use in connection with traditional open surgical procedures. For the purposes herein, either an endoscopic instrument or an open instrument may be utilized with the electrode assembly described herein. Different electrical and mechanical connections and considerations may apply to each particular type of instrument; however, the aspects with respect to the electrode assembly and its operating characteristics remain generally consistent with respect to both the open or endoscopic designs.

FIG. 1 shows a bipolar forceps 10 for use with various endoscopic surgical procedures and generally includes a housing 20, a handle assembly 30, a rotating assembly 80, a knife actuator 70 and an electrode assembly 105 having opposing jaw members 110 and 120 that mutually cooperate to grasp, seal and divide tubular vessels and vascular tissue. More particularly, forceps 10 includes a shaft 12 that has a distal end 16 configured to mechanically engage the electrode assembly 105 and a proximal end 14 that mechanically engages the housing 20. The shaft 12 may include one or more suitable mechanically-engaging components that are designed to securely receive and engage the electrode assembly 105 such that the jaw members 110 and 120 are pivotable relative to one another to engage and grasp tissue therebetween.

The proximal end 14 of shaft 12 mechanically engages the rotating assembly 80 to facilitate rotation of the electrode assembly 105. In the drawings and in the descriptions that follow, the term “proximal”, as is traditional, will refer to the end of the forceps 10 that is closer to the user, while the term “distal” will refer to the end that is further from the user. Details relating to the mechanically cooperating components of the shaft 12 and the rotating assembly 80 are described in commonly-owned U.S. patent application Ser. No. 10/460,926, now U.S. Pat. No. 7,156,846, entitled “VESSEL SEALER AND DIVIDER FOR USE WITH SMALL TROCARS AND CANNULAS” filed on Jun. 13, 2003.

Handle assembly 30 includes a fixed handle 50 and a movable handle 40. Fixed handle 50 is integrally associated with housing 20 and handle 40 is movable relative to fixed handle 50 to actuate the opposing jaw members 110 and 120 of the electrode assembly 105 as explained in more detail below. Movable handle 40 and knife actuator 70 are of unitary construction and are operatively connected to the housing 20 and the fixed handle 50 during the assembly process. Housing 20 is constructed from two component halves 20 a and 20 b that are assembled about the proximal end 14 of shaft 12 during assembly. Switch assembly 200 is configured to selectively provide electrical energy to the electrode assembly 105.

As mentioned above, electrode assembly 105 is attached to the distal end 16 of shaft 12 and includes the opposing jaw members 110 and 120. Movable handle 40 of handle assembly 30 imparts movement of the jaw members 110 and 120 from an open position wherein the jaw members 110 and 120 are disposed in spaced relation relative to one another, to a clamping or closed position wherein the jaw members 110 and 120 cooperate to grasp tissue therebetween.

Referring now to FIG. 2, an open forceps 100 includes a pair of elongated shaft portions 112 a and 112 b each having a proximal end 114 a and 114 b, respectively, and a distal end 116 a and 116 b, respectively. The forceps 100 includes jaw members 120 and 110 that attach to distal ends 116 a and 116 b of shafts 112 a and 112 b, respectively. The jaw members 110 and 120 are connected about pivot pin 119 that allows the jaw members 110 and 120 to pivot relative to one another from the first to second positions for treating tissue. The electrode assembly 105 is connected to opposing jaw members 110 and 120 and may include electrical connections through or around the pivot pin 119. Examples of various electrical connections to the jaw members are shown in commonly-owned U.S. patent application Ser. Nos. 10/474,170, 10/284,562 10/472,295, 10/116,944 and 10/179,863, now U.S. Pat. Nos. 7,582,087, 7,267,677, 7,101,372, 7,083,618 and 7,101,371 respectively.

Each shaft 112 a and 112 b includes a handle 117 a and 117 b disposed at the proximal end 114 a and 114 b thereof that each define a finger hole 118 a and 118 b, respectively, therethrough for receiving a finger of the user. As can be appreciated, finger holes 118 a and 118 b facilitate movement of the shafts 112 a and 112 b relative to one another, which, in turn, pivot the jaw members 110 and 120 from the open position wherein the jaw members 110 and 120 are disposed in spaced relation relative to one another to the clamping or closed position wherein the jaw members 110 and 120 cooperate to grasp tissue therebetween. A ratchet 130 may be included for selectively locking the jaw members 110 and 120 relative to one another at various positions during pivoting.

More particularly, the ratchet 130 includes a first mechanical interface 130 a associated with shaft 112 a and a second mating mechanical interface 130 b associated with shaft 112 b. Each position associated with the cooperating ratchet interfaces 130 a and 130 b holds a specific, i.e., constant, strain energy in the shaft members 112 a and 112 b, which, in turn, transmits a specific closing force to the jaw members 110 and 120. The ratchet 130 may include graduations or other visual markings that enable the user to easily and quickly ascertain and control the amount of closure force desired between the jaw members 110 and 120.

As best seen in FIG. 2, forceps 100 also includes an electrical interface or plug 202 that connects the forceps 100 to a source of electrosurgical energy, e.g., an electrosurgical generator similar to generator 500 shown in FIG. 1. Plug 202 includes at least two prong members 202 a and 202 b that are dimensioned to mechanically and electrically connect the forceps 100 to the electrosurgical generator 500 (See FIG. 1). An electrical cable 210 extends from the plug 202 and securely connects the cable 210 to the forceps 100. Cable 210 is internally divided within the shaft 112 b to transmit electrosurgical energy through various electrical feed paths to the electrode assembly 105.

One of the shafts, e.g. 112 b, includes a proximal shaft connector/flange 140 that is designed to connect the forceps 100 to the source of electrosurgical energy such as an electrosurgical generator 500. More particularly, flange 140 mechanically secures electrosurgical cable 210 to the forceps 100 such that the user may selectively apply electrosurgical energy as needed.

FIG. 3 depicts an end effector assembly according to an embodiment of the present disclosure shown generally as end effector 300. End effector assembly 300 includes an upper jaw member 301 and lower jaw member 302. A cutting member or thread-like member 303 spans across the gap between jaw member 301 and jaw member 302. End effector assembly 300 may be used to cut tissue in two modes. In a first mode, thread-like member 303 may be used to cut tissue grasped between jaw members 301 and 302. The tissue may or may not be sealed. In a second mode, thread-like member 303 is stretched between jaw members 301 and 302 to cut tissue that is not grasped by jaw members 301 and 302. This mode may be similar to the use of a surgical scalpel where thread-like member 303 acts a cutting blade. Thread-like member 303 may move between jaw members 301 and 302 to cut the tissue using a saw-like movement.

Thread-like member 303 may be a single filament or composed of multiple filaments bound and tied together or braided. Each filament may be made from a polymer, metal, alloy, optical fiber, composite material, or the like. The portion of thread-like member 303 used to cut tissue may have an irregular surface along the axial direction where the irregularity may be formed by twisted filaments, a barbed structure, abrasive particles attached to thereto, or the like. Thread-like member 303 may also be made from a resistive conductor and coupled to an energy supply that would heat thread-like member 303 to facilitate cutting.

Alternatively, thread-like member 303 may be a fiber waveguide that emits an electromagnetic field to be absorbed by tissue in order to heat the tissue. Thread-like member 303 may be coupled to an energy source (not shown), which may be a stand alone unit or included in generator 500 (FIG. 1) that supplies the electromagnetic energy to thread-like member 303. The fiber waveguide may be an optical fiber waveguide and the energy source may supply optical energy to thread-like member 303. In the portion of thread-like member 303 that directly contacts tissue, waveguiding conditions, such as total internal reflection conditions, may be frustrated and the optical energy leaves thread-like member 303 and penetrates tissue. A rugged side-lit fiber or an optical periodic structure such as long period fiber gratin can be fabricated into thread-like member 303 to increase coupling of energy into the tissue.

As shown in FIG. 3, one end 303 a of thread-like member 303 is secured to a distal end of jaw member 301. Thread-like member 303 is also coupled to a drive member 305 that is configured to move a cutting portion of thread-like member 303 into gap “G” between jaw members 301 and 302 as will be described hereinbelow with reference to FIGS. 4A-7. Drive member 305 may be actuated by a trigger (not shown). Thread-like member 303 moves along a channel 304 in jaw member 302.

With regard to FIGS. 4A and 4B, FIG. 4A depicts the thread-like member 303 before thread-like member 303 is transitioned into a cutting mode and FIG. 4B, shows thread-like member 303 at the final stage of tissue cutting. As shown in FIGS. 4A and 4B, end effector assembly 300 includes a drive member 305 having a drive shaft 307 and guiding rolls 306 attached to the distal end of drive shaft 307. Drive shaft 307 may include a spring component to provide tension and resilience for thread-like member 303 for any width of gap “G”. Drive shaft 307 pushes guiding rolls 306 distally causing thread-like member 303 to move into a cutting mode as shown in FIG. 4B.

As thread-like member 303 is moved into the gap between jaw member 301 and 302, thread-like member 303 cuts tissue disposed between jaw members 301 and 302. As long as end 303 a of thread-like member 303 is secured to jaw member 301 and the other end of thread-like member 303 is being moved, the portion of thread-like member 303 contacting tissue shifts along thread-like member 303 during movement through the tissue. This reduces the path for which a particular portion of thread-like member 303 contacts tissue thereby reducing contamination of thread-like member 303 by the tissue fragments.

FIGS. 5A and 5B depict an end effector assembly according to another embodiment of the present disclosure shown generally as 500. As shown in FIG. 5A, thread-like member 503 is secured at a proximal portion of end effector assembly 500. Thread-like member 503 is substantially similar to thread-like member 303. Thread-like member 503 extends distally through guiding rolls 506 a and 506 b of drive member 505 and is looped around guiding roll 508 at the distal end of jaw member 501. In this arrangement, when shaft 507 of drive member 505 is pushed distally (arrow “D”), two cutting portions 503 a, 503 b are moved into the space between jaw members 501 and 502. Additionally, pushing drive member 505 distally also results in movements along the direction of thread-like member stretching as shown by arrows “X”, “Y” and “Z”. The movement of cutting portions 503 a and 503 b along arrows “Y” and “Z” respectively, provide a saw-like operation for thread-like member 303 that eases cutting of tissue.

With regard to FIGS. 6A and 6B that show an end effector assembly 600 according to another embodiment of the present disclosure, FIG. 6A depicts a spring 610 before spring 610 is transitioned into a cutting mode, and FIG. 6B shows spring 610 at the final stage of tissue cutting. Spring 610 may be a thin bow-shaped spring made from a shape memory alloy or the like. The distal end of spring 610 may be secured to jaw member 601 with a hinge 612. The proximal end of spring 610 may be moved by drive member 605, which includes drive shaft 607 and guiding roll 606, in a channel 620 in jaw member 602. As drive member 605 is pushed distally, a cutting portion 614 of spring 610 moves into position between the distal end of jaw members 601 and 602 to cut tissue placed therebetween.

FIG. 7 depicts an end effector assembly according to another embodiment of the present disclosure. As can be seen in FIG. 7, thread-like member 704 is formed as a continuous loop that is operatively connected to a drive drum 710. When drive member 705 is pushed distally so that cutting portion 703 of thread-like member 704 is positioned between distal end of jaw members 701 and 702, rotation of drive drum 710 causes cutting portion 703 of thread-like member 704 to act as a saw, e.g. a band saw. An ultrasonic transducer 720 may be included to increase the efficiency of cutting portion 703. Ultrasonic transducer 720 may cause cutting portion 703 to excite ultrasonic waves.

While several embodiments of the disclosure have been shown in the drawings and/or discussed herein, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. The claims can encompass embodiments in hardware, software, or a combination thereof. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto. 

What is claimed is:
 1. An end effector assembly, comprising: a first jaw member and a second opposing jaw member configured to grasp tissue therebetween; a thread-like member disposed between the first jaw member and the second jaw member having a first end fixed to a distal end portion of the first jaw member and a portion movably coupled to the second jaw member; and a drive member operably connected to the second jaw member and configured to move the thread-like member distally from a first position to a second position, wherein the thread-like member cuts tissue when transitioned from the first position to the second position.
 2. The end effector assembly of claim 1, wherein the drive member further comprises: a drive shaft having a rod component; and at least one guiding roll configured to guide the thread-like member between the first position and the second position.
 3. The end effector assembly of claim 1, wherein the thread-like member is a bow shaped spring.
 4. The end effector assembly of claim 3, wherein the bow shaped spring is coupled to the at least one jaw member with a hinge.
 5. The end effector assembly of claim 1, wherein a cutting portion of the thread-like member is formed from twisted filaments.
 6. The end effector assembly of claim 1, wherein a cutting portion of the thread-like member includes a resistive conductor.
 7. The end effector assembly of claim 1, wherein a cutting portion of the thread-like member includes a fiber wave guide.
 8. The end effector assembly of claim 7, wherein the fiber wave guide is an optical fiber.
 9. The end effector assembly of claim 8, wherein the optical fiber includes a side-lit fiber or a long period fiber grating.
 10. A method for cutting tissue using an end effector assembly including a first jaw member and a second opposing jaw member and a thread-like member disposed between the first jaw member and the second jaw member the thread-like member having a first end fixed to a distal end portion of the first jaw member and a portion movably coupled to the second jaw member by a drive member, the method comprising: sealing tissue between the pair of opposing jaw members; and activating the drive member to move the thread-like member distally from a first position to a second position to cut the sealed tissue.
 11. The method according to claim 10, wherein the thread-like member is a bow shaped spring.
 12. The method according to claim 10, wherein the bow shaped spring is coupled to the at least one jaw member with a hinge.
 13. The method according to claim 10, wherein a cutting portion of the thread-like member is formed from twisted filaments.
 14. The method according to claim 10, wherein a cutting portion of the thread-like member includes a resistive conductor.
 15. The method according to claim 10, wherein a cutting portion of the thread-like member includes a fiber wave guide.
 16. The method according to claim 15, wherein the fiber wave guide is an optical fiber.
 17. The method according to claim 16, wherein the optical fiber includes a side-lit fiber or a long period fiber grating. 